Troubleshooting 6 Common John Deere LT155 Problems and Solutions (from a Pro)

The John Deere LT155 lawnmower is a powerhouse garden tractor, much-adored for its ability to tackle significant acreage, and perfect for tasks from mowing the lawn to ploughing snow. However, as one wise farmer told us, “Even the best workhorses aren’t without a hiccup or two.”

A well-used LT155 may give your lawn an uneven cut, a telltale sign of bent or rusted blades. Or perhaps you’ve turned the key only to be met with silence. If so, a fouled or old spark plug could be the culprit, preventing a successful ignition.

Most Common Problems with John Deere LT155 Lawnmower

This troubleshooting guide will list the 6 most common problems, and their solutions, ensuring your John Deere LT155 is always ready to go.

1. Cuts Unevenly

The John Deere LT155 lawn mower may experience times when it cuts certain types of lawns or weeds unevenly. I’ve seen this happen a lot actually. This can be caused by a number of factors, including slightly bent or rusted blades that need replacing.

Symptoms and Causes

SymptomPotential Cause
Cuts unevenlySlightly bent or rusted blades that need replacing

Problems and Solutions

ProblemSolution
Slightly bent or rusted bladesReplace the blades

Step by Step Solutions on How to Fix Cuts Unevenly Problems

How to Replace the Blades on a John Deere LT155 Lawn Mower

Why it’s important

Replacing the blades on your lawn mower is important to ensure that it continues to cut evenly and efficiently. Over time, blades can become bent or rusted and may need to be replaced.

Steps to replace the blades

  1. Before attempting to perform any maintenance on your machine, always consult your operator’s manual for detailed directions and safety information.
  2. Park the mower on a level surface and disengage the mower blades.
  3. Locate the blade bolts on the underside of the mower deck.
  4. Use a wrench to loosen and remove the blade bolts.
  5. Remove the old blades from the mower deck.
  6. Install the new blades onto the mower deck, making sure they are properly aligned and secured with the blade bolts.
  7. Tighten the blade bolts securely.

Tips

  • Make sure to use the correct size wrench for the blade bolts.
  • Take note of how the old blades were installed so you can install the new blades in the same orientation.
  • Be careful when handling the blades as they can be sharp.

2. Lawnmower Won’t Start

If your John Deere LT155 lawnmower won’t start and there is no spark, it could be due to an issue with the spark plug. The spark plug is responsible for igniting the fuel in the cylinder head and if it’s not installed correctly or if it’s dirty or not connected to its cable, it can prevent the lawnmower from starting.

Symptoms and Potential Causes

SymptomPotential Cause
No sparkSpark plug is not connected to its cable
No sparkSpark plug dirty
No sparkSpark plug not connected to its cable

Problems and Solutions

ProblemSolution
Spark plug is not connected to its cableCheck that the spark plug is installed correctly in the cylinder head
Spark plug dirtyClean the spark plug
Spark plug not connected to its cableCheck that the spark plug is connected to its cable

Step by Step Solutions on How to Fix When the Lawnmower Won’t Start

Check that the spark plug is installed correctly in the cylinder head

  1. Locate the spark plug on your John Deere LT155 lawnmower. It should be near the cylinder head.
  2. Check that the spark plug is screwed in tightly and is sitting flush with the cylinder head.
  3. If the spark plug is loose, tighten it using a spark plug wrench.

Clean the spark plug

  1. Locate the spark plug on your John Deere LT155 lawnmower.
  2. Remove the spark plug from the cylinder head using a spark plug wrench.
  3. Use a wire brush or spray-on cleaner to remove any dirt or debris from the spark plug.
  4. Check the gap between the center and ground electrodes using a feeler gauge and adjust if necessary according to your lawnmower’s specifications.
  5. Reinstall the spark plug and tighten it using a spark plug wrench.

Check that the spark plug is connected to its cable

  1. Locate the spark plug on your John Deere LT155 lawnmower.
  2. Follow the cable from the ignition coil to the spark plug.
  3. Check that the cable is securely attached to the spark plug.

It’s important to perform these checks and maintenance tasks to ensure that your lawnmower starts and runs smoothly. A dirty or improperly installed spark plug can prevent your lawnmower from starting, so taking these steps can help you avoid potential issues.

3. Engine Surging

Engine surging in the John Deere LT155 lawnmower can be caused by a variety of issues, including dirty fuel, carburetor problems, or an issue with the ignition system. These issues can reduce the fuel flow into the engine, causing it to run lean and surge. It’s important to identify and address the underlying cause of the engine surging to prevent further damage to your lawnmower.

Symptoms and Potential Causes

SymptomPotential Cause
Engine surgingDirty fuel
Engine surgingCarburetor problems
Engine surgingIgnition system issue

Problems and Solutions

ProblemSolution
Dirty fuelDrain and replace fuel
Carburetor problemsClean or rebuild carburetor
Ignition system issueCheck and replace ignition components as needed

Step by Step Solutions on How to Fix Engine Surging

Drain and replace fuel

  1. Locate the fuel tank on your John Deere LT155 lawnmower.
  2. Place a container under the fuel tank to catch any fuel that may spill.
  3. Remove the fuel cap and use a siphon pump to drain the fuel from the tank into the container.
  4. Dispose of the old fuel properly according to local regulations.
  5. Refill the fuel tank with fresh, clean fuel.

Clean or rebuild the carburetor

  1. Locate the carburetor on your John Deere LT155 lawnmower.
  2. Turn off the fuel supply to the carburetor and remove the air filter.
  3. Remove the carburetor from the engine by disconnecting the throttle and choke cables and removing any mounting bolts or screws.
  4. Disassemble the carburetor and clean all parts using carburetor cleaner and compressed air.
  5. If necessary, replace any worn or damaged parts with new ones.
  6. Reassemble the carburetor and reinstall it on the engine, making sure to reconnect the throttle and choke cables and any mounting bolts or screws.

Check and replace ignition components as needed

  1. Locate the ignition coil on your John Deere LT155 lawnmower.
  2. Check for any visible signs of damage or wear on the ignition coil and spark plug wire.
  3. Use a multimeter to test the resistance of the ignition coil according to your lawnmower’s specifications.
  4. If necessary, replace any damaged or worn ignition components with new ones.

It’s important to perform these checks and maintenance tasks to ensure that your lawnmower runs smoothly and efficiently. Dirty fuel can clog your carburetor and reduce engine performance, while a dirty or damaged carburetor can prevent your lawnmower from starting or running properly. Ignition system issues can also prevent your lawnmower from starting, so checking and replacing ignition components as needed can help you avoid potential issues.

4. Engine Trouble

Engine trouble in the John Deere LT155 lawnmower can be caused by a variety of issues, including old gas, dirty air filters, or a faulty spark plug. These issues can reduce the performance of your lawnmower and cause it to run poorly or not start at all. It’s important to identify and address the underlying cause of the engine trouble to prevent further damage to your lawnmower.

Symptoms and Potential Causes

SymptomPotential Cause
Engine troubleOld gas
Engine troubleDirty air filter
Engine troubleFaulty spark plug

Problems and Solutions

ProblemSolution
Old gasDrain and replace fuel
Dirty air filterClean or replace air filter
Faulty spark plugClean or replace the air filter

Step by Step Solutions on How to Fix Engine Trouble in general on this model

Drain and Replace the Fuel

  1. Locate the fuel tank on your John Deere LT155 lawnmower.
  2. Place a container under the fuel tank to catch any fuel that may spill.
  3. Remove the fuel cap and use a siphon pump to drain the fuel from the tank into the container.
  4. Dispose of the old fuel properly according to local regulations.
  5. Refill the fuel tank with fresh, clean fuel.

Clean or replace the air filter

  1. Locate the air filter on your John Deere LT155 lawnmower.
  2. Remove the air filter cover and take out the air filter.
  3. If the air filter is dirty, clean it using compressed air or replace it with a new one if it’s too dirty to be cleaned.
  4. Reinstall the air filter and replace the air filter cover.

Check and replace the spark plug as needed

  1. Locate the spark plug on your John Deere LT155 lawnmower.
  2. Remove the spark plug wire from the spark plug.
  3. Use a spark plug wrench to remove the spark plug from the cylinder head.
  4. Check the condition of the spark plug and replace it with a new one if necessary.
  5. Reinstall the spark plug and attach the spark plug wire.

It’s important to perform these checks and maintenance tasks to ensure that your lawnmower runs smoothly and efficiently. Old gas can clog your carburetor and reduce engine performance, while a dirty air filter can prevent your lawnmower from starting or running properly. A faulty spark plug can also prevent your lawnmower from starting, so checking and replacing it as needed can help you avoid potential issues.

5. Hydrostatic Transmission Problems

Hydrostatic transmission problems in the John Deere LT155 lawnmower can be caused by a variety of issues, including a broken driving axle or metal hose. Cavitation can also occur, preventing the system from creating pressure. To fix cavitation, it’s necessary to clean the hydraulic transmission system. It’s important to identify and address the underlying cause of the hydrostatic transmission problems to prevent further damage to your lawnmower.

Symptoms and Potential Causes

SymptomPotential Cause
Hydrostatic transmission problemsBroken driving axle
Hydrostatic transmission problemsBroken metal hose
Hydrostatic transmission problemsCavitation

Problems and Solutions

ProblemSolution
Broken driving axleReplace driving axle
Broken metal hoseReplace metal hose
CavitationClean hydraulic transmission system

Step by Step Solutions on How to Fix Hydrostatic Transmission Problems in a DIY manner

Replace Driving Axle 

Consult your operator’s manual or contact a John Deere dealer for detailed instructions.

Replace Metal Hose

Consult your operator’s manual or contact a John Deere dealer for detailed instructions.

Clean hydraulic transmission system

  1. Locate the hydraulic transmission system on your John Deere LT155 lawnmower.
  2. Check the system for any damage or leaks.
  3. Clean the pump and add more fuel if necessary.
  4. Purge the hydraulic transmission system to remove any air that may have entered the system.

It’s important to perform these checks and maintenance tasks to ensure that your lawnmower runs smoothly and efficiently. A broken driving axle or metal hose can prevent your lawnmower from moving, while cavitation can prevent the hydraulic transmission system from creating pressure. Cleaning the hydraulic transmission system can help fix cavitation and improve the performance of your lawnmower.

6. Fuel Pump Issues

Fuel pump issues in the John Deere LT155 lawnmower can be caused by a clogged fuel tank. Dirt or debris in the tank can choke it up and slow down the flow of fuel. This can prevent your lawnmower from starting or running properly. It’s important to identify and address the underlying cause of the fuel pump issues to prevent further damage to your lawnmower.

Symptoms and Potential Causes

SymptomPotential Cause
Fuel pump issuesClogged fuel tank

Problems and Solutions

ProblemSolution
Clogged fuel tankClean fuel tank

Step by Step Solutions on How to Fix Fuel Pump Issues

Clean Fuel Tank

  1. Locate the fuel tank on your John Deere LT155 lawnmower.
  2. Place a container under the fuel tank to catch any fuel that may spill.
  3. Remove the fuel cap and use a siphon pump to drain the fuel from the tank into the container.
  4. Dispose of the old fuel properly according to local regulations.
  5. Clean the inside of the fuel tank using a clean cloth or brush to remove any dirt or debris.
  6. Refill the fuel tank with fresh, clean fuel.

It’s important to perform this maintenance task to ensure that your lawnmower runs smoothly and efficiently. A clogged fuel tank can prevent your lawnmower from starting or running properly, so cleaning it can help you avoid potential issues.

How We Created These Problems And Solutions Troubleshooting Guide

To create this troubleshooting guide, a thorough analysis of common problems with John Deere LT155 lawn mowers was conducted. The focus was on identifying symptoms and their potential causes. The importance of each problem was determined based on its frequency and impact on the mower’s performance. 

A variety of sources, including user manuals, forums, and expert advice, were consulted to gather information on the issues and their solutions. These were then organized in order of relative importance. The aim was to provide a comprehensive and user-friendly guide that addresses both common and uncommon problems, helping users troubleshoot and resolve issues effectively—enhancing their overall experience with the John Deere LT155 lawn mower.

Given These Problems, Should You Sell and Replace Your Existing John Deere LT155?

I’ve spent years working with John Deere LT155s — believe me, these machines are resilient. Sure, you might encounter a bent blade or a dusty air filter now and again. But a little elbow grease can make all the difference, reviving your trusty tractor every time. Every repair, from replacing a rusted blade to unclogging a blocked fuel tank, adds to its tale of reliability.

Still, if you’re running a never-ending cycle of changing spark plugs or tussling with a stubborn hydrostatic transmission, it could be time to ponder an upgrade. There’s no shame in looking for a new model, especially if frequent repairs are eating into your time.

In fact, the latest models offer the same John Deere sturdiness, but with a dash of cutting-edge technology. And if your good old LT155 seems to strain under heavy-duty tasks, it might be worth considering a bigger, more capable model. Bigger tasks require bigger tools, after all.

Remember, no matter what path you take, John Deere will always be at your side. Here’s to efficient, smooth mowing and fewer mechanical setbacks!

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